Pygmy Sesame Plants For Mechanical Harvesting

ABSTRACT

Pygmy sesame plants having the py/py recessive gene and a character selected from non-dehiscence or improved non-dehiscence and a method for breeding the same are disclosed. 
     Methods for improved sesame agriculture comprising growing a pygmy sesame line having py/py gene and a character selected from non-dehiscence or improved non-dehiscence are disclosed.

CROSS REFERENCE TO RELATED APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

TECHNICAL FIELD

This invention concerns sesame plant breeding and providing sesame plantvarieties appropriate for mechanized harvesting.

BACKGROUND OF THE INVENTION

Sesame, or Sesamum indicum, is a tropical annual cultivated worldwidefor its oil and its nut flavored seeds. The sesame plant has capsulesfound at its leaf axils, and these capsules which contain the sesameseed. Upon maturity in nature, the capsules holding the sesame seedsbegin to dry down, the capsules normally split open, and the seeds fallout. Commercially, the harvester tries to recover as much seed aspossible from mature capsules. From ancient times through the present,the opening of the capsule has been the major factor in attempting tosuccessfully collect the seed. Harvesting methods, weather, and plantcharacteristics all contribute to the amount of seed recovered.

The majority of the world's sesame is harvested manually. With manualnon-mechanized methods, it is desirable for the sesame seed to fallreadily from the plant. Manual harvesting is labor intensive. Efforts tomechanize or partially mechanize harvesting met with limited success.

A breakthrough was accomplished when non-dehiscent (ND) sesame wasdeveloped and patented by Derald Ray Langham. ND sesame was found topossess the proper characteristics which would enable mechanicalharvesting without the seed loss disadvantages reported with priorvarieties.

U.S. Pat. Nos. 6,100,452; 6,815,576; 6,781,031; 7,148,403; and 7,332,652each disclose and claim non-dehiscent sesame cultivars having variouscharacteristics.

An improved non-dehiscent sesame (IND) class of sesame was laterdeveloped by Derald Ray Langham. IND sesame, through increasedconstriction, better adhesion between the false membranes, and improvedplacenta attachment, holds more seed than prior sesame types, asmeasured four weeks after a crop is ready for harvest (could have beencombined). The IND characteristics offer advantages for certain growingapplications.

The sesame plant generally grows to a height of about 52-249 cm. Mostcommercially grown sesame is approximately 120-160 cm in height. Shorterlines of sesame have been reported, but heretofore none have beensuitable for total mechanical harvesting.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts the plant architecture of seven lines of sesame includinga line which contributed pygmy genes (K28p) in a method of breedingpygmy sesame, three Sesaco varieties used as parents (Sesaco 25 “S25”,Sesaco 26 “S26”, and Sesaco 27 “S27”), and the three pygmy progeny(D50p, D51p, and D54p).

FIG. 2 is a perspective environmental view of a typical farm combinepoised to begin mechanical harvesting of sesame plants in the field.

FIG. 3 is a more detailed perspective view of the reel (2) of combine(1) shown in FIG. 2

FIG. 4 is a cross section along line 4,5 in FIG. 3 depicting theoperation of combine (1) harvesting standard (tall) height non-dehiscentsesame plants (10).

FIG. 5 is a cross section along line 4,5 in FIG. 3 depicting theoperation of combine (1) with pygmy non-dehiscent sesame plants (10) ofthe invention.

FIG. 6 depicts the lineage of D51p.

FIG. 7 depicts the lineage of D50p.

FIG. 8 depicts the lineage of D54p.

FIG. 9 depicts the number of node pairs of the seven lines.

FIG. 10 depicts the average internode length of the seven lines.

FIG. 11 depicts the seed weight per capsule of the seven lines.

FIG. 12 depicts a comparison of yields of the varieties and pygmy linesin various environments.

FIG. 13 depicts the shaker shatter resistance of the seven lines.

DETAILED DESCRIPTION OF THE INVENTION

Pygmy sesame plants suitable for mechanical harvesting, havingnon-dehiscence (ND) or improved non-dehiscence (IND) are disclosed.Further, methods for breeding the same and methods of use for pygmysesame having ND or IND characteristics are herein disclosed.

The pygmy lines of sesame disclosed herein define a new category ofplant architecture and are suitable for mechanized harvest. Further, thepygmy sesame of the invention is advantageous in methods of sesame cropgrowing on a large scale. The pygmy sesame lines can be grown in higherpopulations than taller sesame varieties, are advantageous in mechanizedcombining processes, are resistant to lodging as compared with tallervarieties, reduce the need for weed management, and exhibit a higherharvest index.

The genetic characteristics of the pygmy plant have now been studiedthrough crosses, and it has now been determined that the pygmy allele isPY/py. A sesame plant which phenotypically is pygmy is homozygous forpygmy (py/py). A sesame plant phenotypically normal may be either PY/PYor PY/py. The genetics are further discussed in Table II.

The height of the py/py sesame line of the invention will vary withgrowing conditions, but generally will be between about 52 and 110 cm.The height of the plant is measured from the ground to the top of thehighest capsule with viable seed. (For more details on the character seeTable V, Character No. 5. The plant architecture includes the plantheight and two other characters discussed below: height of first capsule(Character No. 6) and capsule zone length (Character No. 7). The sum ofthe two latter characters is the plant height. The plant architecture ofseven compared sesame lines is shown in FIG. 1.

The pygmy sesame line described herein has the characteristic of ND orIND. The ND or IND characteristic allows for mechanized harvesting ofthe crop. In order to impart the ND or IND character to the pygmy line,a sesame line having this character is used in the breeding method. Suchsesame lines were disclosed in U.S. Pat. Nos. 6,100,452; 6,815,576;6,781,031; 7,148,403; and 7,332,652 (non-dehiscent sesame cultivars)which are herein incorporated by reference and U.S. patent applicationSer. No. 12/041,257, filed Mar. 3, 2008 (method for breeding improvednon-dehiscent sesame (IND)); U.S. patent application Ser. No.12/041,205, filed Mar. 3, 2008 (improved non-dehiscent sesame cultivarS32, representative seed having been deposited under ATCC accessionnumber PTA-8888); U.S. patent application Ser. No. 12/049,705, filedMar. 17, 2008 (improved non-dehiscent sesame cultivar S30,representative seed having been deposited under ATCC accession numberPTA-8887); U.S. patent application Ser. No. 12/533,972 filed Jul. 31,2009 (improved non-dehiscent sesame cultivar S27, representative seedhaving deposited under ATCC accession number PTA-10184), and U.S. patentapplication Ser. No. 12/565,095, filed Sep. 23, 2009 (non-dehiscentblack sesame cultivar S55, representative seed having been depositedunder ATCC accession number PTA-10185, which is a stable, commerciallysuitable sesame line providing the only black sesame that can bemechanically harvested); which applications are herein incorporated byreference as if set forth in their entirety. Filed concurrently withthis application is U.S. patent application (Attorney Docket Number SESA3400 PTUS) Ser. No. ______, filed ______ which discloses a pygmy varietySesaco 70 (S70) made in accordance with the teachings of the presentapplication and which is herein incorporated by reference as if setforth in its entirety herein.

The ND and IND lines identified, or other ND or IND lines can be used inbreeding a pygmy sesame line to impart such characteristics to the line.The genetics are further explained in Table III.

The ND or IND character is important to the pygmy line. Without ND orIND characteristics, a sesame line is considered “shattering.” In orderto get an economic yield using shattering lines, a sesame crop has to bemanually harvested, which entails cutting it manually at physiologicalmaturity. After manual cutting, the sesame plants are shocked, dried,and then threshed. Threshing involved manually beating the dried cutstalks to separate the sesame seed from the inedible chaff or plantmaterial. Finally, the seed needed to be cleaned away from undesiredmaterial.

ND or IND allows for use of machines for all of the harvest process withno manual labor. When manual harvesting is necessary, shorter sesamelines are disadvantageous because harvesting such lines requires anincreased level of manual labor and stooping for the workers. Thus, theND or IND character of the pygmy sesame lines disclosed herein avoid thedisadvantage inherent in shorter sesame lines that must be harvestedmanually.

Because the ND or IND pygmy lines have less shatter, they present anadvantage to mechanical harvesting employing a combine. A combine is afarm machine that cuts and threshes grain or other crops in oneoperation. (“combine” stands for “combined” harvester-thresher). Withmodern combines the maximum plant height should be under 180 cm, but itis preferred that the varieties be below 150 cm (Langham, D. R. and T.Wiemers, 2002. “Progress in mechanizing sesame in the US throughbreeding”, In: J. Janick and A. Whipkey (ed.), Trends in new crops andnew uses, ASHS Press, Alexandria, Va.). With taller plants, the combinereels push the plants forward before pulling them into the combines.Even with shatter resistance, this pushing forward and pulling backshatters seed to the ground. Even when plants are below 150 cm, there isstill some shattering caused by the reel.

Pygmy lines produced according to the method disclosed herein are lessthan about 110 cm in height, have non-dehiscence or improvednon-dehiscence, and are more efficiently mechanically harvested thansome taller varieties with a farm combine. Preferably, the pygmy linesproduced according to the method of the invention are between about 52cm and 110 cm, most preferably as short as possible while stillproviding sufficient yield for an economical return.

When the pygmy lines made according to the method of the invention aremechanically harvested with a combine, the reel of the combine brings inthe sesame into the cutter bar without first pushing the plants forward.The pygmy lines made according to the invention fall into the header ofthe combine and are easily fed by the auger into the feeder housing ofthe combine as illustrated in FIGS. 2-5.

FIG. 2 is a perspective environmental view of sesame plants (10) asgrown in a field wherein a combine (1) is ready to begin mechanicalharvesting. Standard combine (1) has a platform header (2). The headerhas a reel (3) that rotates in direction (5) toward the sesame plants(10) growing in a field. The combine platform has a cutter bar (4) whichcuts the stems of the plants (10). FIG. 2 is provided for illustrativepurposes only, and there has been no attempt to accurately portray thenumber of sesame plants per square meter. In practice, there can be from10 to 100 plants per square meter.

Reel (3) illustrated in FIG. 2 has five transverse bars or “bats” (3 a).Reel (3) also has center axle (3 b) and end frame (3 d) which asillustrated is a pentagon shape. End frame (3 d) has five spoke-likestructures (3 c) attached thereto extending essentially radially tocenter axle (3 b). Reels such as Reel (3) as illustrated in FIG. 2 areknown as “bat reels” and are the most common type of reel used tomechanically harvest sesame crops.

In practice, combine (1) will be driven by an operator in direction (6)shown in FIG. 2. Reel (3) rotates in direction (5) concurrently. As reel(3) rotates, bats (3 a) contact plants (10) and pull them toward header(2) and cutter bar (4) which cuts the plants. Continued rotation of reel(3) pulls the cut plants further into the header (2), and the internaloperations of combine (1) (not shown) which separate seed from plantmaterial (“threshing”).

FIG. 3 provides a more detailed perspective view of reel (3) of combine(1) to put FIGS. 4 and 5 in context. Here bats each of the five bats (3a) are individually labeled. Also represented is auger (7) of the headerwhich functions to move the plant material from header (2) into thethreshing apparatus (not shown) internal to combine (1). The view forFIG. 4 and FIG. 5 is shown by the 4,5 in FIG. 3.

Now referring to FIG. 4 which illustrates mechanical harvesting ofstandard (tall) non-dehiscent sesame plants and FIG. 5 which illustratesmechanical harvesting of pygmy non-dehiscent sesame plants in accordancewith the present invention. Note that non-dehiscent sesame is requiredfor effective mechanical harvesting, and was developed and patented bythe inventor as previously discussed. FIG. 4 and FIG. 5 are crosssectional views of Reel (3) of FIG. 3 along the line indicated in FIG. 3with representative plants illustrated as they are harvested.

FIG. 4 shows operation of combine (1) with standard (tall) heightnon-dehiscent sesame plants (10). As previously stated in the context ofFIG. 2, reel (3) rotates in direction (5) clockwise towards the plants.The sesame plants (10) have stems (11) and capsules (12). The plantshave shed their leaves prior to harvest. Capsules (12) are shown withopen tips (13) and exposed seed (14) as best seen in the enlargement ofa capsule (12) from plant (10 a) provided in FIG. 4. Each capsule (12)contains an average of 70 seeds.

Still referring to FIG. 4, when combine (1) is in operation, bats (3 a1-5) shown in cross-section, will strike the plants. Bat (3 a 1) isshown having struck a portion of plant (10 a) whereupon one or morecapsules (12) may be torn off and/or some of the seed (14 a) may bereleased and may fall on the ground. Seed released in this way will notbe recovered by the header (2) unless the momentum of the reel sweepssome of the seed (14 b) which is released by impact of bat (3 a 1) onplant (10 a) into the header (2). As reel (3) continues to rotate indirection (5), bat (3 a 1) will contact plant (10 b) and bend it awayfrom header (2) before bat (3 a 5) or another bat comes around and pullsplant (10 b) toward the header, as illustrated with bat (3 a 2) andplant (10 c).

As the stem (11) reaches the header, cutter bar (4) cuts the plant andthe remaining material is swept into the combine.

FIG. 5 illustrates the advantages that the pygmy non-dehiscent sesame ofthe present invention provides with respect to mechanical harvesting.Plant (10 d) is not pushed away or bent down by bat (3 a 1) and thusthere is no seed similarly positioned to seed (14 a) in FIG. 4. Theincidence of capsule tear-off is greatly reduced and any seed that doesseparate from the capsules upon contact between bat (3 a 1) and plants(10) will be in a position such as seed (14 c) which will be swept intothe header by momentum. Therefore, the pygmy non-dehiscent sesameprovides an advantage in reduction of seed loss during mechanicalharvesting.

Because the pygmy lines made according to the method disclosed hereinare shorter than typical commercial lines of sesame suitable formechanical harvesting, pygmy sesame lines do not bridge over the augerof the combine as do the taller varieties. Even though taller branchedvarieties usually flow through the combine auger better than single stemtaller varieties, pygmy sesame lines still present an advantage overeven branched taller varieties because pygmy sesame lines can be plantedin higher populations in terms of plants per meter and in closer rowspacing resulting in more plants per square meter. The auger of thecombine can easily handle a high population of single stem pygmyvarieties.

The height of the first capsule is measured from the ground to thebottom of the lowest capsule on the main stem. With modern combines, forall sesame varieties, 15 cm is an acceptable value for the height of thefirst capsule in level fields, while the optimum height is 30 cm. Asshown in FIG. 1, the original pygmy sesame used in the breeding methoddisclosed herein exhibited a height of first capsule below 15 cm, whichwas below the minimum height for the typical modern combine. However,progeny fell in between the minimum of 15 cm and the optimum of 30 cm.It is preferable, to plant a pygmy variety made according to theinvention in a fairly level fields to enable standard combines tocapture all of the capsules (and enclosed seed) into the combine. Byutilizing level fields, the height of first capsule will be fairlyconsistent and the combine can be set at a level to maximize capture ofplants with capsules at the appropriate level.

The shorter height of the pygmy sesame line of the invention furtherprovides the additional advantages of lodging resistance and the abilityto plant higher populations in a given area than would be possible withtaller plants.

The amount of lodging is highly correlated to the amount of windresistance. Taller plants present more resistance to the wind, and thusthere is more torque on the base of the plant. When excessive torque isapplied, the plants may break over. Pygmies present less resistance tothe wind than taller varieties. In addition, the wind speed diminishescloser to the ground, and thus there is less force hitting pygmy sesameas compared to taller varieties.

Pygmies are advantageous for high population sesame planting methods.Pygmies are advantageously employed in a method of agriculturecomprising increasing the number of sesame plants per linear foot in aplanting row. Pygmies are also advantageously employed in a method foremploying closer row spacing in a sesame field planting resulting inmore plants per square meter.

Close row spacing is advantageous because the plants provide a canopymore rapidly, thereby inhibiting weed growth. Weeds are “shaded out” bya canopy because weeds sprouting from the ground under the canopy die orare stunted from the lack of sunlight. By planting in closer rowspacing, the farmer has lower inputs (e.g. lower resources that are usedin farm production, such as chemicals, equipment, feed, seed, andenergy) since he does not have to cultivate (weed). Pygmy sesame plantedin 15 to 20 cm rows can be used in a method of sesame agriculture whichomits the step of cultivation. Omitting the cultivation is advantageousin that it reduces the growing costs since cultivation requires fuel(diesel), operator hours, and maintenance.

The pygmy sesame line of the invention can thrive with more plants perlinear meter and make the practice of overplanting more productive.Farmers generally engage in the practice of overplanting in order toensure the maximum production of their acreage. If normal height sesameis planted, and the overplanting results in more than 10 plants perlinear meter, some plants will shade out others. The shaded plantseither die out, resulting in self-thinning, or survive as “minor plants”as defined in Langham, D. R. 2007. “Phenology of sesame,” In: J. Janickand A. Whipkey (ed.), Issues in New Crops and New Uses, ASHS Press,Alexandria, Va. The minor plants do not produce a commensurate amount ofseed for the moisture and nutrients that the minor plants use. Incontrast, when pygmy sesame according to the invention is overplanted,less shading occurs with a high population within a row. The minorplants are more productive

In high population normal height sesame planting, plants may compete forlight, leading to a release of auxins that make the plants grow faster.This faster growth may result in taller plants which may also havethinner, weaker stems. Increased height and stem thinness may make theplant more susceptible to lodging. Heretofore known varieties of sesamethroughout the world could not be planted in high population or closerow spacing because of the associated increase in the susceptibility tolodging resulting therefrom.

Pygmy sesame has a higher harvest index than taller sesame varieties.The harvest index is the ratio of weight of the seed to the weight ofthe entire plant including seed. Since there is a set amount of moistureand fertility available to any crop in a given field, it is generallymore advantageous for a plant to use those resources to produce seedthan to use the resources to make the vegetative parts of the plant suchas leaves, stems, and capsules. While there must be a balance (since thevegetative parts are necessary to the plant to capture sun and conductphotosynthesis to generate energy which is used to make seed), seed isthe reason that sesame crops are planted.

A second advantage of high harvest index is that most modern combinesare designed to clean grain that has a low proportion of dockage andforeign matter to seed. The higher the harvest index, the cleaner thesesame will be which exits the combine. This reduces cleaning andtrucking costs.

Pygmy sesame is advantageous as a crop since the high populationplanting reduces the number of weeds that plague crops of tallervarieties of sesame.

One of the more difficult parts of raising mechanized sesame is weedmanagement. With manual methods of raising sesame, manual labor wasemployed to remove weeds by hand, but in modern mechanized agriculture,weed management employs mechanical operations and/or herbicides.Mechanical operations include disking and harrowing prior to planting toeliminate all the weeds in the field and then cultivating (breaking upthe surface soil around the plants with a farm implement called acultivator in order to destroy weeds) after the crop gets to asufficient height. However, it is difficult to cultivate sesame becauseit develops slowly in the first 30 days while it is putting its rootdown (Langham, D. R. 2007. “Phenology of sesame,” In: J. Janick and A.Whipkey (ed.), Issues in New Crops and New Uses, ASHS Press, Alexandria,Va.). It takes almost 20 days before a cultivator can be used in asesame field without damaging the sesame.

In addition to mechanical means, preemergence herbicides may be usedwhich are applied after planting and before the sesame seedlings emergefrom the ground. These herbicides provide 30-40 days of protection frommost weeds. Sesame is primarily a rotation crop for cotton, corn, andsoybeans. Such crops may rely on the use of glyphosate to kill all weedsexcept the crop. The plants are genetically modified organisms (GMO) inthat the gene that protects these crops from the glyphosate is insertedinto the germplasm. Although no GMO sesame is known, producing aglyphosate resistant sesame would not provide a solution to the weedproblem because as a rotation crop for cotton, corn, and soybeans aglyphosate-resistant sesame would be an undesired plant (“weed”) inthose crops, which would be unacceptable to the farmers. Further, somecountries to which sesame is marketed do not permit GMO corps.

Another method of weed control relies upon the growth of the plants inthe adjoining rows. As the plants grow, the respective leafs from plantsin adjoining rows will be relied upon to prevent new weeds in the spacebetween the rows from getting sunlight (e.g. “shade out” the weeds). Theadjoining rows are said to “close in.” However, this may take anadditional 20-50 days before the area between the rows is shaded out.The time required is influenced by the variety of the sesame (height ofthe plant and branching) and the spacing between rows. Standard rowspacing for sesame (75 to 100 cm) favors taller varieties for shadingout which generally have more branching as well.

It has now been found that pygmy sesame (py/py) can be used in a methodfor close row planting wherein the rows are about 20 to 40 cm apart andprovide for rapid closing up. Planting at 20 cm (the row spacing usedfor wheat but heretofore not employed for sesame), the rows close inwithin 20 days, thereby shading out weeds between rows. Not having asuitable over the top herbicide (e.g., an herbicide that can be sprayedon the field and kill the weeds not the sesame plants) for sesame, thefaster the crop can close up and shade out weeds, the better.

Advantages of Improved Non-Dehiscent Pygmy Geographical Distribution

Currently sesame is primarily grown as a rotation crop on farms thatgrow cotton, sorghum, peanuts, sunflowers and soybeans. Farmers of thesecrops usually have row equipment for these crops which allows for rowspacing of 50 to 100 cm, usually 75 to 100 cm. The equipment includesrow planters and cultivators. The existing farm equipment works well forplanting standard height sesame as it will close up between rows toaddress weeds which would otherwise be harmful to the crop.

However, in areas in which the primary crop is wheat, farmers possessrow equipment (drills) for planting in 15 to 20 cm rows and likely donot have cultivators. While some drill equipment may be modified by thefarmer for wider row spacings, other drills cannot. Even if theequipment can be modified, such farmers are still limited to plantingsesame in fields that are clean of weeds in the absence of a cultivator.

Pygmy sesame may be used in a method of close row planting, thusallowing farmers to use drill equipment adapted to planting in 15 to 20cm rows. This will allow expansion of sesame growth to areas in whichthe equipment for standard row of 75 to 100 cm are rare.

Advantages of Improved Non-Dehiscent Pygmy Lower Inputs

Pygmy sesame planted in 15 to 20 cm rows can be used in a method ofsesame agriculture which omits the step of cultivation (weeding).Omitting the cultivation is advantageous in that it reduces the growingcosts since cultivation requires fuel (diesel), operator hours, andmaintenance.

Pygmy sesame can be used in a method of sesame agriculture employingincreasing the speed of combining crops by employing pygmy sesame havinga high harvest index. The combines can move through the field fasterbecause there is less plant matter going through the combine. Generally,the price charged by custom operators for combining is based on amountof time required. Therefore, reducing the time required reduces the costof combining. Pygmy sesame can be used in a method of sesame agriculturein which sesame is grown under low moisture conditions and/or lowfertility conditions. Since pygmy lines will produce more seed per unitof moisture/fertility than non-pygmy lines, pygmy lines are suitable foruse in such a method.

The following paragraphs provide further details about thecharacteristics of the pygmy sesame of the invention.

Sesame plants have been studied for their response to seasonal andclimatic changes and the environment in which they live during thedifferent phases and stages of growth and development. This type ofstudy, called “phenology”, has been documented by the inventor inLangham, 2007, supra, ¶49.

Table I summarizes the phases and stages of sesame, and will be usefulin describing the present invention.

TABLE I Phases and stages of sesame. No. Stage/Phase Abbrev End point ofstage DAP ^(z) weeks Vegetative VG Germination GR Emergence 0-5 1−Seedling SD 3^(rd) pair true leaf length =  6-25 3− 2^(nd) Juvenile JVFirst buds 26-37 1+ Pre-reproductive PP 50% open flowers 38-44 1−Reproductive RP Early bloom EB 5 node pairs of capsules 45-52 1  Midbloom MB Branches/minor plants 53-81 4  stop flowering Late bloom LB 90%of plants with no 82-90 1+ open flowers Ripening RI Physiologicalmaturity  91-106 2+ (PM) Drying DR Full maturity FM All seed mature107-112 1− Initial drydown ID 1^(st) dry capsules 113-126 2  Latedrydown LD Full drydown 127-146 3  ^(z) DAP = days after planting. Thesenumbers are based on S26 in 2004 Uvalde, Texas, under irrigation.

Dwarf lines are identified by having a low plant height, shortinternodes, and high capsule density with a resulting high harvestindex. Most dwarf lines had triple capsules per leaf axil, but dwarflines can have a single capsule per leaf axil. The latter lines have ashorter internode length than the triple capsules still conveying theimage of high capsule density. In the world germplasm there are shortlines that do not have short internodes, have few capsules, and havelittle yield. These lines are not considered to be dwarves.

In order to breed a shorter sesame line, a sesame dwarf plant may beused in the breeding method. A preferred dwarf is on that has a genewhich, when crossed, will exhibit as many as 25% short plants in the F2,indicating a recessive py/py gene. A suitable sesame dwarf is K28p whichmay be used in a breeding method to provide characteristics of pygmybecause the py/py gene is recessive creating more short plants in the F2generation. An ND or IND sesame line should also be used in the breedingmethod.

Table II summarizes the paragraphs above using the followingdesignators: T=tall normal plants with no dwarf or pygmy genes, P=purepygmy, and D=pure dwarf genes.

TABLE II Height of plant crossing results based on types of parentsParents F1 F2 Comments T and P T T and P Usually in the F2 there areless than 5 to 20% P and the rest T with no observed intermediateheights. The py/py allele is recessive and the expected ratio would be25% py/py. However, the same gene that shortens the internode lengths,shortens the hypocotyl of the seedling, which in turn reduces theprobability of emerging above the surface of the soil after germinating.The germination rates are around 5% when planted deep in compactedsoils, and around 20% when planted shallow in light soils. In the F3 andsubsequent generations, the P will be pure P. Some of the T willsegregate 5-20% P, while some of the T will be pure T, and the latterwill be pure T in subsequent generations. T and D T T and D Usually inthe F2 there is a range of plant heights between the two parents. Therewill be less than 5% plants that are as short as the D, and no plantsthat are shorter than the D parent. In the F3 the T will generally be T,the D will generally by D, while the intermediates will go in bothdirections. D and P D D and P Usually in the F2 there are less than 5 to20% P and the rest D with no intermediate heights. In the F3 andsubsequent generations, the P will be pure P. Some of the D willsegregate 4-20% P, while some of the D will be pure D, and the latterwill be pure D in subsequent generations. P and P P P From the F1 on,all of the progeny are P. T and T T T From the F1 on, all of the progenyare T. There is heterosis in sesame and in the F1 many progeny will betaller than either parent, but in subsequent generations the majority ofthe selections will be between the heights of the two parents. There canalso be be selections that are taller and selections that are shorterthan either parent.

In creating pygmy IND lines, Table II explains the probabilities facingthe breeder in developing a P, while Table III below summarizes theprobabilities of getting ND and IND using the following symbols:X=shattering, C=close to ND, N=ND, and I=improved ND.

TABLE III Shatter resistance crossing results based on types of parentsParents ^(z) F1 F2 Comments X and N X X, C, and N Usually in the F2there are less than 2% N Most X and often zero N. Selecting C will alsorarely end up segregating N. It is preferred to perform enough crossesand plant out as many F2 plants as feasible and only select N plants. Xand I X X, C, N, and I Same as above Most X C and N C X, C, and N X arerare and although it is preferred to Most C select N plants, there aremany C plants with good commercial characters that have the potential tosegregate N. C and I C X, C, N, and I Same as above Most C N and N X, C,and N X, C, N, and I X and C are rare but the characters that Most Nproduce N can fall apart. Although I are rare, the first I were a resultof N and N crosses. N and I X, C, N, and I X, C, N, and I X and C arerare. Higher probability of Most N getting I than above. I and I X, C,N, and I X, C, N, and I X and C are rare. Highest probability of Most Igetting I, but there are many N ^(z) There is no reason to make a crosswhere one of the parents is not an “N” or “I”

Prior to the method disclosed herein, all known shatter resistant sesameparents were tall ND (TN) or tall IND (TI). All potential pygmy parentswhere pygmy shattering (PX). Genetically, there is no difference inusing the pygmy as a male or female, i.e., PN and PI can be achievedwith either parent as a female. Pragmatically, it is better to use theTN/TI parent as the female. A capsule produced by a cross will have thecharacteristics of the female plant. Thus, the capsule(s) will be N/Iand the seed will not shatter out as the capsule dries down. It ispreferable to use a TI over a TN. Shatter resistance is produced bymultiple genes and TI lines have more of the appropriate genes. Table IVshows the flow of selections by crossing a PX male by a TI female.

TABLE IV Results of crossing a tall IND line by a pygmy shattering linePlant/ Generation Pygmy Comments Cross TI The crossed plant and capsuleshave the characters of the female. F1 TX T and X characters are dominantover P and I. F2 TX The majority of the progeny will be TX, and theseshould not be carried forward PI A PI plant should be selected. In 100progeny, the probability is against a single PI plant, and thus 300-1,000 progeny plants should be planted from each F1 plant. It ispreferred to achieve PI plants by performing dozens of crosses betweenTI and PX lines and planting about 300 progeny from each cross in theF2. Using this methodology, one will obtain multiple PI plants withdifferent genetic backgrounds. PN/PC There is a greater probability offinding a PN plant than a PI plant and an even greater probability offinding a PC plant. PN plants are selected to carry further if there aretoo few PI selections. The same with PC. PX Of the pygmies from thiscross, the highest probability is PX, but these are only carried furtherif there are no PI/PN/PC selections. TI/TN/TC Each of these selectionshas the potential to segregate into a PI/PN, but these are usually onlytaken if there are no pygmy selections. F3 and PI There are many genesinvolved in ND and IND. A PI F2 beyond may segregate to more or lessshatter resistance. The pygmy character is stable and will be pure fromthe F2 on. Finding a PI is the first step of developing a commerciallyacceptable PI variety. As discussed below, other characters shouldpreferably be introduced into the line to result in an acceptable yieldand biotic and abiotic resistances. PN/PC Any PI found in theseselections are normally selected and carried forward. PN plants withgood agronomic characters may be carried forward, but the probability ofa PC segregating to a PN/PI after the F3 generation is low, and thus noPC plants are selected to carry further. TI/TN/TC Theoretically, onethird of these F2 selections will be pure T. The other two thirds cansegregated PI/PN and are carried forward.

Once a PI line is found, the PI plants should be used as the male parentinstead of the PX lines.

In an example of the method of the invention, D54p was crossed againstmany TI lines. This aggregated desirable characters by using buildingblocks. Sixty-two PN and fifty PI (for a total on 112 lines) have beendeveloped based on this methodology. Although the preference is PI,there are PN lines with higher yield in some environments. Therefore,both PN and PI lines may become varieties.

In order to become a commercial variety, the line should exhibitcomparable yield to existing varieties. The following tables show theprogenitor K28p, three varieties (S25, S26, and S27) and three progeny(D51p with its genealogy depicted in FIG. 6; D50p with its genealogydepicted in FIGS. 7; and D54p with its genealogy depicted in FIG. 8).Table V shows the characters that determine potential yield. There aresome characters presented that are neutral, but are presented becausethey affect the other characters.

TABLE V Characters that determine potential yield Character K28p S25D51p S26 D50p S27 D54p Pygmy alleles py/py PY/PY py/py PY/PY py/py PY/PYpy/py (Character 1) The pygmy allele is recessive with the py/py beinghomozygous pygmy and PY/PY being homozygous normal. In the homozygouspygmy state, the plant height, height of first capsule, and internodelength are shortened as shown below. K28p S25 D51p S26 D50p S27 D54pBranching style U B U B B B U (Character 2) The potential amount of truebranching in a line. Subjective rating based on the following values: U= Uniculm - no branching except weak branches in open B = True branchesU.S. Pat. No. 6,781,031 provides more detail as to the definition of“true branches” As shown above, there are uniculm and branched pygmies.In some pygmy lines there are branches that are not expressed. In orderfor a branch to develop, sunlight needs to hit the growing tip in theleaf axil. With shorter internodes, the sunlight does not penetrate thecanopy to enable the branches to develop. There are pygmies such as D50pabove with slightly longer internodes that will branch. Branching is notas important for pygmies because they are capable of being planted inhigh populations where branches do not contribute a significant amountto the yield. K28p S25 D51p S26 D50p S27 D54p Number of 3 1 1 1 1 1 1capsules per leaf The predominant number of capsules per leaf axil inthe middle half of axil (Character the capsule zone. Subjective ratingbased on the following values: 3) 1 = Single 3 = Triple U.S. Pat. No.6,781,031 presents more detail as to how to differentiate singlecapsules per leaf axil from triple capsules per leaf axil. There aresingle lines that have a few nodes with triple capsules, and triplelines have single capsules at the bottom and top of the plant. A 1998Sesaco study showed that single capsule lines averaged 0.91 capsules perleaf axil and the triple capsule lines averaged 1.64 which is not quitedouble. In addition, in a 1999 Sesaco study, the axillary capsulesaveraged 79.4% seed weight per capsule of the central capsules. Based onsource/sync issues, triple capsules do not imply higher yields. Underthe growing conditions most encountered (rainfed crops in low rainfallareas), single capsule lines are preferred. Triple capsule lines are notsuitable unless the height of the the first capsule is high enough topermit mechanized harvest. K28p S25 D51p S26 D50p S27 D54p Days to 88100 99 106 98 106 102 physiological The number of days from plantinguntil 50% of the plants reach maturity physiological maturity. The valueis based on the average of a minimum of (Character 4) three plots. Thevalues within Sesaco range from 77 to 140 days with an average of 97.The ripening phase of sesame is from the end of flowering untilphysiological maturity. Physiological maturity (PM) is defined as thepoint at which ¾ of the capsules have seed with final color. In mostlines, the seed will also have a seed line and tip that are dark. Theconcept of physiological maturity in sesame was developed by M. L.Kinman (personal communication) based on the concept of determining theoptimum time to cut a plant and still harvest 95-99% of the potentialyield. When the seed has final color, the seed can germinate under theproper conditions. If the plant is cut at physiological maturity, mostof the seed above the ¾ mark will go to final color and are matureenough to germinate, but will not have as much seed weight. Since ineven a fully mature plant, there is less seed weight made at the top ofthe plant, this loss of seed weight does not seriously affect thepotential seed weight of the plant Although present harvest methods letthe plants mature and go to complete drydown, PM is important becauseafter that point, the crop is less susceptible to yield loss due tofrost or disease. The PM is also important if the crop is to be swathedor harvest aids are to be applied. The range of PM for pygmy lines ispreferably similar to standard height ND or IND current varieties. Thepresence of pygmy genes will not be a range inhibiting factor in that acomparable PM may be selected. K28p S25 D51p S26 D50p S27 D54p Height ofPlant 52 138 87 153 84 141 90 (cm) (Character The height of the plantfrom the ground to the top of the highest capsule 5) with viable seed. Aminimum of 3 representative plants are measured and averaged. The valueswithin Sesaco range from 52 to 249 cm with an average of 135 cm. Theplant architecture shows the plant height and two other charactersdiscussed below: height of first capsule and capsule zone length. Thesum of the two latter characters is the plant height. The plantarchitecture of the 7 lines is shown in FIG. 1. K28p is too short anddoes not have enough yield potential to be commercially viable. Thethree pygmy progeny are below 100 cm and have sufficient yield to becommercially viable. In the first combine test with D54p, the reelbrought the sesame into the cutter bar without pushing the plantsforward, and the short plants fell into the header and were easily fedby the auger into the feeder housing of the combine. As long as there issufficient yield, shorter lines are preferable for mechanical harvestwith a combine. K28p S25 D51p S26 D50p S27 D54p Height of first 9 57 2457 18 45 24 capsule (cm) The height of the first capsule from the groundto the bottom of the lowest (Character 6) capsule on the main stem. Aminimum of 3 representative plants (the same as are used for height ofplant) are measured and averaged. The values within Sesaco range from 20to 193 cm with an average of 54 cm. As shown in FIG. 1, the originalsource souce of pygmy was below the minimum height, but the progeny fallin between the minimum of 15 cm and the optimum of 30 cm. This shortheight of the first capsule dictates that the pygmies be planted infairly level fields if the combine is to get all of the capsules (andenclosed seed) into the combine bin. However, just as a certain amountof shattering is acceptable as long as there is a good yield, it may beacceptable to leave some capsules (seed) that would be below the cutterbar of the combine. The countours of the field should be consideredbefore planting pygmies. K28p S25 D51p S26 D50p S27 D54p Capsule zone 4281 63 96 66 96 66 length (cm) The capsule zone extends from the bottomof the lower capsule on the (Character 7) main stem to the top of thehighest capsule with viable seed on the main stem. The data is derivedby subtracting the height of the first capsule from the height of theplant. A minimum of 3 representative plants (the same as are used forheight of plant) are measured and averaged. The values within Sesacorange from 18 to 188 cm with an average of 81 cm. Technically, thecapsule zone should include the capsule zones on all of the branches.However, when mechanically planting without any manual thinning, thepopulations vary considerable. In low populations the plant will havemany branches, and in high populations the plant may have no branches.In comparing lines across fields, environments, and years, the capsulezone length of the main stem can be used effectively to select progenyto carry forward. Since the capsule zone contains the plant production,on initial examination of the figures above, it would seem that thepygmy necessarily has less yield than the normal lines. However, asshown below with the number of node pairs and the internode length,pygmies have the same potential yield. K28p S25 D51p S26 D50p S27 D54pNumber of node 16 29 28 27 25 32 31 pairs (Character The number ofcapsule node pairs from the lowest capsule node to the 8) highest nodewith capsules with viable seed on the main stem of the plant. A minimumof 3 representative plants (the same as are used for height of plant)are measured and averaged. The values within Sesaco range from 10 to 54node pairs with an average of 25. The count is made after the plantsstop flowering. On opposite and alternate arranged leaves, each pair ofleaves is counted as one node pair. In some lines, there are threeleaves per node for at least part of the plant, and those are counted asone node pair. In some plants, flowers may not have produced capsules onone or more the leaf axils in a node. These node pairs should still becounted. This is not a capsule count; it is intended to denote thenumber of node pairs that the plant tried to set capsules. Triplecapsule lines generally have fewer node pairs. In comparing lines, thevalue is compared to the other lines with the same branching style andnumber of capsules per leaf axil. In years when the amount of moistureavailable to the plant is irregular, node pairs can become veryirregular, particularly on triple capsule lines. In the upper portionsof the plant, it may become easier to count the capsule clusters anddivide by 2. While it is possible to count node pairs after leaves havefallen, it is much easier to count while the leaves are still on theplant. FIG. 9 compares the number of node pairs of the seven lines. Theprogenitor K28p has fewer node pairs, but as can be seen above, pygmyprogeny was selected that had similar number of node pairs to the normalparent. There are pygmy lines with more node pairs than either parent.K28p S25 D51p S26 D50p S27 D54p Average 2.7 2.9 2.3 3.5 2.7 2.7 2.3internode length The average within the capsule zone. The samerepresentative plants within capsule used above are used for this data.The height of the plant, the height of the zone (cm) first capsule, andthe number of nodes are used for the following formula: (Character 9)height of plant subtracted by height of the first capsule and thendivided by the number of node pairs on the main stem. Within Sesaco therange is between 1.09 and 8.09 cm with an average of 3.35 cm. Theinternodes at the bottom of the capsule zone are longer than theinternodes at the top of the plant. Generally, triple capsule per leafaxil lines have longer internodes than single capsule lines. In triplecapsule lines the axillary capsules should be as tight to the stem aspossible in order to avoid rubbing off the plants in the wind, By beingtight, the intenodes need to be almost of long as the capsule. Normallya stem has 4 sides and the central capsules rotate 90 degrees from thecentral capsules in the node below. Thus, in a few lines there can be anexception where the central capsules tuck in between the axillarycapsules above and the internode length is shorter than the capsulelength. Triple capsule lines generally have longer internode lengthsbecause there needs to be room on the stem to place the extra capsules.There are triple capsule lines that can have shorter internode lengthsby either having shorter capsules (less seed) or by angling the axillarycapsules away from the stem (easy to break off capsule in plants rubbingin the wind). The shorter internode character by itself is not adefinitive pygmy identifier. As can be seen above there is some overlapbetween normals and pygmies. FIG. 10 compares the internode lengths.Pygmies are shorter and have a lower height of the first capsule thannormal lines because of the short internode length. It is also thisshort internode that allows the pygmies to have a sufficient number ofnode pairs without increasing the plant height. Aside from keeping theplants shorter, the internode length has another implication: the leavesend up shielding the leaf axil from sunlight. As stated in Langham(supra), in order to form a branch sunlight needs to reach the leafaxil. There are pygmy lines that have branching genes that will rarelybranch, and yet when they are crossed against a non-branched normal, inthe F1 they have branches indicating that the pygmy had branching genes.These lines have a branching genotype and a uniculm phenotype. When apygmy such as D50p has longer internodes, then there can be branching.K28p S25 D51p S26 D50p S27 D54p Seed weight per 0.160 0.213 0.183 0.2330.256 0.210 0.221 capsule (SWC) The weight of the seed in a capsule fromthe center of the capsule zone. (g) (Character The value is based on theaverage of a minimum of three samples. After 10) the plants arephysiologically mature, two capsules are taken from five plants from themiddle of the capsule zone. On three capsule per leaf axil lines, onecentral capsule and one axillary capsule should be taken from the sameleaf axil. This test is known as the 10cap test and several measures arederived from this test. The capsules are dried out to insure the seed isdry, and then the seed is threshed out of the capsules and weighed. Thetotal weight is divided by ten to get the seed weight per capsule. Thecapsules can be sampled from physiological maturity through completedrydown without an effect on this character. After drydown, onlycapsules with all their seed are taken. Thus, this test cannot be doneon shattering lines after drydown. Within Sesaco the range is between0.053 and 0.476 g with an average of 0.221 g. Generally, the capsules inthe middle of the capsule zone have the highest SWC on the plant.Generally, triple capsule lines have a lower SWC than single capsulelines. The axillary capsules have less less SWC and in a triple capsuleline, and half of the capsules in each sample are axillary capsules.When the pygmies were first discovered, it was feared that SWC might bea limiting factor in yield. However, as shown in FIG. 11, there arepygmy lines that have comparable SWC to the present varieties. Being atriple capsule line, the progenitor K28p has a very low SWC. Thepresence of pygmy genes will not be a yield inhibiting factor in that acomparable SWC may be selected. K28p S25 D51p S26 D50p S27 D54p Non-leafharvest NT 31.7 NT 29.6 NT 28.2 36.7 index (%) (not (Character 11)tested) The ratio of seed to the whole plant without leaves. The data isderived by dividing the seed weight of a plant by the weight of thestems, capsules, seed, and leaves and converting it to a percentage. Itis time consuming to take the data and it is not taken often, and thusSesaco does not maintain ranges and averages of the values. A trueharvest index measures the weight of the leaves as part of weight of thetotal plant. Sesame presents a unique problem in measuring harvest indexbecause it self-defoliates. The leaves begin to fall before the seed atthe top of the plant has filled. If the plant is cut, dried, and weighedwhile the leaves are still on the plant, then there is less seed weight.If the plant is cut, dried, and weighed after the top seed has filled,there is less plant weight because the leaves have fallen off.Generally, triple capsule lines have higher non-leaf harvest indicesthan single capsule lines. It is misleading to compare single to triplelines because the leaves are not counted. Triple capsule linesnecessarily have larger leaves to produce enough seed in the 3 capsulesin the leaf axil. Non-leaf harvest indices are still very time consumingand have only been done three times by Sesaco. It was found that theindex varies considerably with the environment. In years when there ismore rain and yields are higher, the harvest index is higher than in dryyears. In the limited testing that has been done, the pygmies have hadhigher non-leaf harvest indices than the normal lines. However, it islogical that in the future the ranges of the two will overlap. K28p S25D51p S26 D50p S27 D54p Seed weight - 0.255 0.304 0.270 0.330 0.350 0.3140.326 100 seeds from The weight of 100 seeds taken from the 10cap testswhich are taken from 10cap test (g) the middle of the plant. The valueis based on the average of a minimum (Character 12) of three samples.The 10cap procedures are described under Seed Weight per Capsule(Character No. 10). Once the seed is threshed out of the capsules, 100representative seeds are counted out and weighed. The seed must be dry.Within Sesaco the range is from 0.200 to 0.455 g with an average of0.298 g. The seed weight in the middle of the stem zone is the heaviestseed on the plant. Generally, triple capsule lines have lower hundredweight than single capsule lines. The seed in the axillary capsules issmaller than the seed in the central capsules. The seed from any wholeplant is lower that the seed from the 10cap test because the seed in thetips of the capsules is smaller, the seed in the branches is smaller,the seed at the top of the plant is smaller, and although close in size,most of the seed at the bottom of the plant is smaller. This hundredseed weight from the 10cap test is used because it is simple to take andmore important, there is a high direct correlation between the weight100 seeds from the middle of the plant and the weight of 100 seeds fromthe whole plant. This value is used to compare lines grown under thesame conditions and cannot be considered to be the weight of the lineunder all conditions. The same seed planted in many environments canhave a much as a 94% difference using the lowest as a base or 52%difference using the highest sample as a base. Simply said, in somelines the seed can be close to twice the weight under differingconditions. Pygmies can all produce both small and large seed. Thepresence of pygmy genes will not be a market inhibiting factor in that acomparable hundred seed weight may be selected. K28p S25 D51p S26 D50pS27 D54p Seed color BF BF BF BF BF BF BF The color of the Subjectiverating based on the following values: seed coat WH = White (Character13) BF = Buff TN = Tan LBR = Light brown GO = Gold LGR = Light gray GR =Gray BR = Brown RBR = Reddish brown BL = Black Seed coat color is takenon mature seeds. If there is any abnormal termination, the colors arenot quite as even. The color of immature seed varies. Usually lightseeded lines have tan to light brown immature seed; tan, light brown,gold, brown light gray, and gray lines have lighter immature seed; blacklines can have tan, brown, or gray immature seed. The majority of themarket uses light seed. There are no problems with having light andblack color seed on pygmy lines.

Table VI compares Yield at drydown for ND/IND varieties with that ofpygmies. This value is taken after the plants are dry standing in thefield without cutting and shocking. As a result of winds and rains, theyields in shattering lines are 50 to 100% less than the amount ofpotential yield if the plants are cut when they are green and all seedthat shatters out in the drying process is maintained. Thus there is noyield data for the shattering lines K28p, D51p and D50p. Table VI showsthe highest yield in seven nurseries comparing the best variety and thebest pygmy line. Within each nursery, the lines were grown in comparableconditions.

TABLE VI Yield of varieties and pygmies ND/IND Variety Pygmy NurseryYield at drydown 1,945 1,682 2006 Uvalde, TX. Irrigated, good fertility.(kg/ha) (Character 14) 1,098 1,170 2007 Uvalde, TX. Irrigated, lowfertility. 1,174 1,564 2007 Lorenzo, TX. Irrigated, low fertility. 1,7491,487 2008 Uvalde, TX. Irrigated, good fertility. 1,426 1,749 2008Uvalde, TX. Semi-irrigated, good fertility. 639 1,413 2008 Lorenzo, TX.Rainfed, low fertility. An extrapolation of the yield of a field bytaking sample yields. On 3 replicated plots, when the plants are dryenough for direct harvest, cut a minimum of 1/5000 of a hectare (Sesacouses 1/2620) in the plot and place the plants in a cloth bag. Thresh thesample in a plot thresher and weigh the seed. Multiply the weight by theappropriate multiplier based on area taken to provide the extrapolatedyield in kg/ha. Under good moisture and fertility the standard heightND/IND varieties have exhibited higher yields when planted at 76 and 100cm row spacing than pygmy lines. However, when there are limits to themoisture or fertility, the pygmies have higher yields than the non-pygmyvarieties and are thus an option for a method of sesame agricultureunder low moisture and/or fertility conditions. .

Table VII discusses factors that influence an ideal yield of a sesamecrop (drought, diseases, pests, and lodging prior to flower termination)or reduce the ideal yield (shatter resistance, lodging after flowertermination, and dry pods on a green plant). Shatter resistance is thecharacter that allows sesame to be left in the field to dry and thenharvested with a combine.

TABLE VI Characters that Influence potential yield K28p S25 D51p S26D50p S27 D54p Shaker shatter 2.2 70.8 14.8 73.0 6.3 72.8 77.4 resistance(%) The amount of seed retention after the capsules are dry, inverted,and (Character 15) put through a shaker. The data is derived from 10captesting as described in the Seed Weight per Capsule (Character No. 10).The capsules should be dried and inverted. The capsules and any seedthat has fallen out should then be placed in flasks on a reciprocalshaker with a 3.8 cm stroke with 250 strokes/min for 10 minutes (seeU.S. Pat. No. 6,100,452). The seed that comes out of the capsules shouldbe weighed as ‘out seed.’ The retained seed should be threshed out ofthe capsules and weighed to compute the ‘total seed’. The shaker shatterresistance (SSR) is computed as a percentage as follows: (total seed −out seed)/total seed. The capsules can be sampled from physiologicalmaturity through complete drydown without an effect on this character.After drydown, only capsules with all their seed are taken. WithinSesaco the values range from 0 to 100% with an average of 56%. After theinitial studies in the development of this rating, the 10cap testing isonly done on lines that are showing visual shatter resistance and arecandidates for a variety. As a result, the average continues to climbover time. SSR is the most important piece of data to determine whethera line has the potential to develop into a variety. Preferably, thisthreshold is at least 65%, and more preferred is a threshold of 70%. Acharacter of IND (improved non-dehiscence - Character No. 18) explainedbelow is most preferred. In U.S. Pat. No. 6,100,452 the original sourcesof ND were identified along with the six characters that were joined toenable ND. Once a line is ND, then that line is used as a parent to passND to shattering lines. While it is necessary to use an ND sesame in abreeding method to produce progeny with the ND characteristic, it may benecessary to make multiple crosses before sucesss is achieved.. FIG. 13compares seven sesame lines. D54p is exemplary of a suitable pygmy line.D54p exhibits both pygmy and ND characters. Both characters arenecessary for the pygmy lines that can be harvested mechanically. Thereis a very low probability of success in crossing a shattering lineagainst lines with ND, because there are six capsule characters thatmust be modified. It is disclosed herein that a preferred method ofbreeding includes passing the pygmy genes from an ND pygmy to an NDnormal as compared with crossing a shattering pygmy with an ND normal.K28p S25 D51p S26 D50p S27 D54p Non-dehiscent XX ND XX ND XX ND ND test(Character A line that has passed the non-dehiscent test of havingshaker shatter resistance 16) >64.9% is considered an ND line inaccordance with U.S. Pat. No. 6,100,452. The values used are: ND =Non-dehiscent line XX = Line that does not pass the non-dehiscent testLines are designated as ND only after they have undergone a minimum of 3shaker shatter resistance tests. In order to be considered an NDvariety, the line must pass the ND threshold in multiple nurseries formultiple years. Varieties which have sufficient seed retention to beclassified as non- dehiscent have been previously disclosed by Sesaco inU.S. Patents U.S. Pat. Nos. 6,100,452; 6,815,576; 6,781,031; 7,148,403;and 7,332,652. The K28p progenitor is a shattering line. Throughbreeding, homozygous py/py pygmy alleles have been joined tonon-dehiscent alleles to produce non-dehiscent pygmy lines. Sixty-two(62) pygmy ND lines have been developed to date. K28p S25 D51p S26 D50pS27 D54p K28p S25 D51p S26 D50p S27 D54p Improved non- Z 6.2 Z 6.5 Z 7.27.5 dehiscent visual Amount of seed in most of the capsules in theplants in a plot four or more weeks rating (Character after the idealharvest time. The value is based on the average on a minimum 17) ofthree plots of a subjective rating based on the percentage of capsuleswith visible seed retention 8 < 100% 7 < 85% 6 < 70% 5 > 55% Z < 55%‘*’, ‘+’ and ‘−’ modifiers can be used. For averages, 0.5 is added for a‘*’, 0.33 is added for a ‘+’, and 0.33 is subtracted for a ‘−’, e.g.,“7+” = 7.33. The data is taken four or more weeks after the idealharvest time by estimating the percentage of capsules that have visibleseed at the top. In the beginning in order to develop an eye for therating, the evaluator should observe all of the capsules and rate eachof them; get a counts of those with no visible seeds (quicker to countthose with visible seeds) and a count of total capsules; and compute apercentage. Once the evaluator is skilled, there is no need to count thecapsules. There is a very high correlation between this rating uponvisual evaluation and the amount of rattling generated by the “drumtest”. The “drum test” consists of placing the fingers from one handabout ½ inch from the center of the main stem and then striking the stemalternately with one finger and then the other finger in rapidsuccession. The human ear can perceive degree of rattling over a range.IND is defined as having no rattle. Degree of rattle in this testcorrelates with loss of increasing amounts of seed as capsules areexposed to weather conditions. Although retention can vary from plant toplant and even within a plant, the overall rating is correlatable withIND. The shattering lines (K28p, D50p, and D51p) and were not ratedsince a prerequisite for the test is non-shattering. S27 and D54p arethe only lines used in the method disclosed herein that passed the INDtest. K28p S25 D51p S26 D50p S27 D54p Improved non- ZZ ZZ ZZ ZZ ZZ INDIND dehiscent test An ND line that passes the rattle test and has avisual IND rating >6.99 is (Character 18) considered IND. A method fortraditional breeding of an IND line is described in U.S. PatentApplication Serial No12/041,257, filed Mar. 3, 2008 which is hereinincorporated by reference as if set forth in its entirety. ND and INDlines should not have id or gs alleles. Subjective rating based on thefollowing values: IND = Improved Non-dehiscent line ZZ = Line that doesnot pass the improved non-dehiscent test Using an IND parent does notguarantee an IND progeny particularly when crossing an IND with ashattering line. Now that the pygmy and IND genes have been joined, D54pwas used as a parent to develop many other IND pygmies whether crossingit against normal IND or ND lines or with crossing it against pygmy INDor ND lines. Through this method, there have been 50 pygmy IND linesdeveloped. K28p S25 D51p S26 D50p S27 D54p Lodging NT 5.0 NT 5.3 NT 6.77.7 resistance The amount of lodging. Average of a minimum of threeplots of a (Character 19) subjective rating based on the followingvalues: 0 to 8 rating 8 = no lodging 7 = Less than 5% of plants lodged 4= 50% of plants lodged 1 = All plants lodged Intermediate values areused. There are three types of lodging: where the plants break at thestem, where the plants bend over but do not break, and where the plantsuproot and bend over. When a plant breaks over, it will rarely produceany new seed, and the existing seed may or may not mature. If there is atotal break, there is no hope, but if there is still some active stemtranslocation through the break, there can be some yield recovery. Themain causes for uprooting of plants are shallow root systems and fieldsthat have just been irrigated or after a heavy rain, creating a softlayer of soil. When a plant bends over early in development, some linesadapt better than others in terms of having the main stems turn up andcontinue flowering. The tips of the branches are usually matted underthe canopy and will rarely turn up, but new branches can develop. As theplants go to drydown and the weight of the moisture is lost, many of thebent plants will straighten up making the crop easier to combine. Thisis a character that can prevent yield if the field lodges early or loseyield if the field lodges late. When there is early lodging, the plantsand leaves block the sun and reduce the amount of possiblephotosynthesis, but the winds can also break plants and/or branches.When there is late lodging, the winds can break plants and/or branches,and if the capsules are dry, the winds can shatter some of the capsules.Winds can also have another late effect - the rubbing of the plantsagainst each other in the wind can rub off capsules. This rubbingnormally is not a problem in early winds because the leaves act as shockabsorbers. The amount of resistance to lodging is directly correlated tostem strength. There are pygmy lines that will lodge and others thatwill not. However, the pygmies have two advantages that increase theirresistance to lodging: (1) They are low to the ground and the wind speedis lower and (2) Being smaller they present less resistance to the wind.Experimental plots grown in the Uvalde nursery were subjected to 65 kphwinds. Most of the pygmy sesame plants stayed upright including the D54pabove. There was less lodging in the pygmy section of the nursery thanin the normal section. K28p S25 D51p S26 D50p S27 D54p Resistance toGood Poor Good Good Good Medium Good drought The relative amount ofresistance to drought. An average of a minimum (Character 20) of 3 plotsof a subjective rating based on the following values using a 0-8 scale:7 = little negative effect from drought 4 = medium negative effect fromdrought 1 = considerable negative effect from drought Intermediatevalues are used. Within Sesaco the values range from 0 to 8 with theaverage changing within nursery. In a year when there is a drought, thisrating can be used to differentiate the effects of the different lines.This is a highly subjective rating requiring a rater that is familiarwith the performance of the line under normal conditions. The rating isbased on how the drought changes the line from normal. Thus, a shortline that does not change significantly in a drought may have a higherrating than a tall line which is affected by the drought even though thetaller line is taller in the drought than the short line. In the absenceof droughts, the 0-8 scale cannot be used. In such case, a rating ofpoor, medium, good, and very good can be used as a subjective ratingbased on observation of the effects of a dry period between irrigationsor rains. Under test conditions where a third irrigation was delayed,the majority of the lines, showed severe wilting in the afternoon withsome lines shedding their lower leaves In contrast, the pygmy linesshowed no wilt. In another test nursery, pygmies and standard heightvarieties were grown on a steep slope that had less moisture. Again, thepygmies never shed their bottom leaves and yielded better than thestandard height varieties. As a result, it is hypothesized that with alower non-leaf harvest index, that the pygmies require less moisture andthus do better in low moisture conditions. K28p S25 D51p S26 D50p S27D54p Composite kill 2.0 5.1 2.9 4.9 3.3 5.8 3.5 resistance The amount ofplants killed by root rots in the Sesaco nurseries. Average (Character21) of a minimum of three plots of a subjective rating based on thefollowing values: Ratings are based on the number of plants killed in aplot. Before physiological maturity (PM), the following ratings areused: 1 = >90% kill before flower termination 2 = >90% kill betweenflower termination and PM. After PM, the following ratings are used: 3= >90% kill 4 = 50 to 89% kill 5 = 25 to 49% kill 6 = 10 to 24% kill 7 =less than 10% kill 8 = no kill On the week a plot reaches PM, a ratingis assigned. The ratings are then taken for 2 additional weeks. Thethree ratings are averaged for a final kill rating. For example, if aplot has a final kill of 766, the average for the plot will be 6.33.When a value of 1 or 2 is assigned, there are no additional ratings andthere is no averaging. Within Sesaco the range is from 1 to 8 with anaverage of 4.52. There are three root diseases that affect sesame inTexas: Fusarium oxysporum, Macrophomina phaseoli, and Phytophtoraparasitica. Between 1988 and the present, spores of these three havebeen accumulated in one small area (1 square km) north of Uvalde, andthus it is an excellent screening area for the diseases. Although eachroot rot attacks sesame in a different way with different symptoms, noeffort is made to differentiate which disease is the culprit in eachplot. Pathological screenings in the past have found all 3 pathogenspresent in dead plants. The comparison above is from a nursery withsevere kill, and all seven lines were compared. In one test, the ratingswere as follows: K28p = 2.0, S25 = 6.4, S26 = 7.0, S27 7.3, and D54p6.8. Despite the low rating of the progenitor K28p, it has been possibleto select for improved kill resistance in some of the progeny such asD54p. K28p S25 D51p S26 D50p S27 D54p Resistance to Poor Good MediumVery Medium Good Medium silverleaf whitefly good (Bemisia Amount ofresistance to the silverleaf whitefly. Average of a minimum ofargentifolii) three plots of a subjective rating based on the followingvalues using a 0 to (Character 22) 8 scale of the % of infected plants:8 = Zero insects 7 = Few insects 4 = Many insects 1 = Insects killingthe plants Intermediate values are used. NT = not tested NEC = noeconomic damage - not enough insects to do ratings Ratings can be donein several ways: 1. Take ratings after the insects are no longerincreasing. 2. Take ratings on consecutive weeks until insects are nolonger increasing and average ratings. 3. Take periodic ratings andaverage ratings. There have been some years (1991-1995) where theincidence of silverleaf whitefly has significantly affected nurseriesand commercial crops. In most years, a few white flies can be seen inthe sesame with no economic damage, possibly due to introduction ofnatural predators of the silverleaf whitefly in crop locations, or tonatural tolerance to whitefly in the newer sesame varieties. Highertemperatures decrease the number of days between generations and highermoisture and fertility have been implicated as possible causes for theincrease the incidence of whiteflies. In the absence of severeinfestations, the 0-8 scale cannot be used In such case, a rating ofpoor, medium, good, and very good are a subjective rating based on therelative amount of infestation. The progenitor K28p is very susceptibleto whiteflies. In the nurseries there is more damage from whitefly tothe pygmy lines, but filtering for resistance has reduced the problemconsiderably. K28p S25 D51p S26 D50p S27 D54p Resistance to 2.0 8.0 2.28.0 7.1 8.0 4.4 green peach Amount of resistance to the green peachaphid. The rating system is the aphid (Myzus same as for the Resistanceto silverleaf whitefly (Character No. 22). persica) There have been someyears (1990-1995) where the incidence of green (Character 23) peachaphid has affected nurseries or commercial crops. In most years, a fewaphids can be seen in the sesame with no economic damage. Unlike thewhitefly where only the southern portion of the US sesame growing areais affected, the green peach aphid has been seen into Southern Oklahoma,but it has been rare. The only commercial fields that have been affectedare planted late and with very susceptible varieties. The green peachaphid attacks pecan groves and the only commercial fields that have beenaffected are near pecan groves. In 1992 there was a severe attack on abreeding nursery in San Angelo, Texas, and hundreds of breeding lineswere discontinued and resistant lines were accelerated. However, aphidsare present in most years and Sesaco maintains “canary” lines in thenurseries to detect the insect. A canary line is very susceptible to thedisease or insect. In 2004, the pygmy lines became the canary lines, andthere began considerable filtering for resistance. The progenitor K28pis very susceptible to the green peach aphid. In the nurseries there ismore damage from green peach aphid to the pygmy lines, but filtering forresistance has reduced the problem considerably. K28p S25 D51p S26 D50pS27 D54p Dry pod on a Yes No No No No No No green stem Dry pod on agreen stem (DPGP) was a very common trait on lines from (Character 24)Asia, but in recent years, breeders in many countries have selected awayfrom this trait, and introductions seldom show the problem. The traitoccurs when there are dry capsules on a plant that still has leaves andflowers. In severe cases, there can be a dry capsule on a leaf axil thathas not shed its leaf. In a manual harvest environment, DPGP is not adesirable character because the practice is to cut the plants as soon asdry capsules appear and shock the plants to dry. The leaves delay dryingand generally the seed towards the top of the plant has not filled. In amechanical harvest environment, DPGP is not as serious a problem becausethe harvest cannot be done until the plant is dry, but it does mean thatthere are dry capsules on the plants longer than necessary. No matterthe degree of shatter resistance, there is some loss of seed, and thelonger the dry capsule is exposed to the elements, the greater theamount of seed loss. The ideal is to have all the seed to the top of theplant filled and the leaves off the plant before the first dry capsuleand all Sesaco varieties have this trait. DPGP is such an easy trait toselect away from that the genetics of the trait has not been studied. Bythe F3 of a cross between a DPGP line and a normal line, the trait hasbeen eliminated. However, it is included in this list because theprogenitor K28p had a severe case of DPGP.

1. A pygmy sesame line, wherein said sesame is py/py and has a characterselected from the group consisting of non-dehiscence and improvednon-dehiscence.
 2. A method for improving the yield and mechanicalharvesting of sesame crops, comprising: planting a pygmy sesame seedline as said sesame crop, said pygmy sesame seed line having both apy/py genetic trait and a character selected from the group consistingof non-dehiscence and improved non-dehiscence.
 3. The method of claim 2,further comprising increasing the number of sesame plants per linearmeter in a planting row as compared with standard practice for non-pygmysesame lines.
 4. The method of claim 2, further comprising employingclose row spacing, resulting in more plants per square meter as comparedwith standard practice for non-pygmy sesame lines.
 5. The method ofclaim 4, wherein said rows are from about 15 to 20 cm apart.
 6. Themethod of claim 2, wherein said pygmy sesame line has a height betweenabout 52 and 110 cm.
 7. The method of claim 6, wherein said sesame linehas a first capsule height from about 15 to about 30 cm.
 8. The methodof claim 2, wherein said mechanical harvesting is done using a combineharvester and the improvement comprises lowering the time required toharvest a given acreage planted with pygmy sesame as compared with thetime required to harvest a non-pygmy sesame line.
 9. The method of claim2, wherein the probability of lodging is reduced.
 10. The method ofclaim 2, wherein the harvest index of said sesame crop is increased. 11.A method of breeding a pygmy sesame line, comprising the steps ofselecting a dwarf sesame line and thereafter making a cross between saiddwarf line and a first standard height sesame line to obtain an F1generation; growing seeds from said F1 generation to obtain an F2generation; selecting pygmy plants from said F2 generation, said pygmyplants characterized by being shorter than said standard height sesameplants, indicating a recessive py/py gene.
 12. The method of claim 11,further comprising crossing said F1 generation with one or more sesamelines and selecting progeny with desired characteristics.
 13. The methodof claim 12, wherein said desired characteristic is non-dehiscence. 14.The method of claim 12, wherein said desired characteristic is improvednon-dehiscence.
 15. The method of claim 11, wherein said dwarf is K28p.